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CsPbBr3 nanoplates (NPs) have shown great potential in diverse optoelectronic applications. Despite the wonderful luminescence properties, the inherent instability of these NPs hinders their use in practical situations. Herein, a facile water‐assisted strategy is reported to synthesize highly stable blue emission CsPbBr3 NPs encapsulated in PbBr(OH). The introduction of water directly into the reaction mixture is pivotal, as it triggers the transformation of bulk CsPbBr3 nanocubes into 2‐D CsPbBr3 NPs within the PbBr(OH) matrix, resulting in the formation of CsPbBr3@PbBr(OH) microbricks. Remarkably, the water content in the reaction mixture allows the control of the number of perovskite layers in the NPs, thus enabling the emission color to be tuned from deep blue to green. The unconventional approach presented herein not only offers a cost‐effective pathway to synthesize blue‐emitting perovskites which are highly stable in a wide variety of polar and non‐polar solvents, but also holds immense potential for propelling the advancement of high‐performance LEDs and other optoelectronic devices. The findings underscore the significance of water in dictating the growth dynamics and emission characteristics of perovskite NPs, paving the way for their practical application. [ABSTRACT FROM AUTHOR]

Quantum‐confined perovskite CsPbBr3 Nanoplatelets (NPLs) have recently emerged as promising blue‐emitting materials for perovskite light‐emitting diodes (PeLEDs). Yet, their susceptibility to optical instability in solid films under ambient conditions poses a significant hindrance. This study introduces a novel chelating strategy that utilizes metal manganese ions and multidentate ligands, markedly improving the structural stability, and emission efficiency of NPLs. The approach involves adding Diethylenetriaminepentaacetic acid (DTPA) to the perovskite precursor solution, which allows for strong coordination to surface [PbBr6]4− octahedrons via its multiple chelation sites. Ensuing metal manganese ion integration during the purification phase addresses Pb2+ and Br− site vacancies, culminating in near‐perfect octahedral structures with significantly fewer vacancies. These metal manganese ions are then further immobilized on the NPLs surface by the chelating effect of unbound DTPA functional groups. The resultant CsPbBr3 NPLs films demonstrate an impressive PLQY of 66%, showcasing remarkable air stability with consistent blue emission for up to 5 days. The CsPbBr3 NPLs‐based PeLEDs show electroluminescence at 460 nm with a current efficiency of 1.07 cd A−1 and a maximum luminance of 220 cd m−2. The proposed chelating strategy positions perovskite NPLs as an extremely promising prospect in future applications of high‐definition displays and high‐quality lighting. [ABSTRACT FROM AUTHOR]

Ammonia as an irreplaceable chemical has been widely demanded to keep the sustainable development of the modern society. However, its industrial production consumes huge energy and releases extraordinary green‐house gases, leading to various environmental issues. To achieve the green production of ammonia is a great challenge that has been extensively pursued recently. In the review, a most promising strategy, electrochemical nitrate reduction reaction (e‐NO3RR) for the purpose is comprehensively investigated to give a full understanding of its development and mechanism and provide guidance for future directions. Particularly, the development of electrocatalysts is focused to realize the high ammonia yield rate and Faraday efficiency for industrial applications. The recent‐developed catalysts, including noble metallic materials, alloys, metal compounds, single‐metal‐atom catalysts, and metal‐free materials, are systematically discussed to review the effects of various factors on the catalytic performance in e‐NO3RR. Accordingly, the strategies, including defects engineering, coordination environment modulating, surface controlling, and hybridization, are carefully discussed to improve the catalytic performance, such as the intrinsic activity and selectivity. Finally, perspectives and challenges are given out. This review shall provide insightful guidance on the development of advanced catalytic systems for the production of green ammonia efficiently in the industry. [ABSTRACT FROM AUTHOR]

Filter‐free color imaging is the long‐pursued solution for its simple structure, low cost, and high stability. However, a spectroscopic unit is still necessary for the current Si‐based imaging unit due to the intrinsic photoresponse properties of Si. Here, the authors demonstrate a filter‐free color‐resolved single‐pixel imaging (SPI) by combining the working mechanism of computational ghost imaging and the response characteristic of perovskite. Benefitting from a broad linear dynamic range (106.5 dB) and a high detectivity (4.03 × 1014 Jones) of the fabricated ultrasensitive MAPbBr3 microwire arrays (MWAs) photodetector, the light attenuation caused by an object can be effectively correlated with its color. The reconstructed images of both transmissive and reflective color objects show a high wavelength resolution reaching 20 nm in the range of 400–540 nm, which is impossible to achieve by commercial silicon‐photodiode‐based ones. This work can open a new door for the image acquisition of color‐sensitive objects and also pave a way for the evolution of the next generation of detectors and cameras with low‐dimensional perovskite materials. [ABSTRACT FROM AUTHOR]

The electrochemical nitrate reduction for green ammonia production is attracting increasing attention, where the catalysts are widely investigated by controlling the compositions or structures to achieve high performance. However, their reconstructions under reduction potentials are inevitable and uncontrollable, leading to uncertain performance, and a confused understanding of the mechanism. In this work, a strategy is proposed by controlling the pre‐catalyst's reconstruction chemistry toward electrochemical nitrate reduction reaction (e‐NO3RR) with superior activity and stability. To demonstrate the idea, a pre‐catalyst is fabricated with α‐Co(OH)2 and Cu(OH)2 (α‐Co(OH)2/Cu(OH)2), which is in situ reconstructed to a tandem catalyst with Cu and β‐Co(OH)2 (Cu/β‐Co(OH)2) under working potential. Cu/β‐Co(OH)2 achieves an optimal Faraday efficiency for ammonia of 97.7% with a yield rate of 3.9 mmol h−1 cm−2 at −0.5 V, outperforming other reported metal‐hydroxide catalysts. The experimental and theoretical results demonstrate that a tandem catalytic mechanism is responsible for the exceptional performance: 1) Cu functions as the donor of nitrite; and 2) β‐Co(OH)2 serves as active sites for generating active hydrogen and reducing nitrogen‐containing groups. This work highlights that the controllable reconstruction toward improved performance can be realized, and provides an insightful understanding of the mechanism, which is helpful for developing active and stable catalysts for various catalytic applications. [ABSTRACT FROM AUTHOR]

Active materials play a crucial role in the performance of phototransistors. However, the discovery of a novel and versatile active material is a big challenge. For the first time, phototransistors with ultrathin niobium‐doped indium oxide (InNbO) active layer are fabricated. The InNbO phototransistors without additional light‐absorbing layers exhibit the performance with a high average mobility of 22.86 cm2 V−1s−1, a turn‐on voltage of −0.75 V, a low sub threshold swing of 0.18 V/decade, and a high on/off current ratio of 5.74 × 108. Detailed studies show that Nb is the key to suppress the free carrier generation due to the strong bonding strength of Nb─O. In addition, the InNbO phototransistors exhibit a very broad spectral responsivity with a photocurrent of 4.72 × 10−4 A, a photosensitivity of 1.69 × 108, and a high detectivity of 3.33 × 1013 Jones under violet (405 nm) light illumination, which is significantly higher than that of the IGZO phototransistors. Furthermore, an active‐matrix quantum‐dot light‐emitting diode pixel circuit based on InNbO phototransistors is demonstrated. The findings not only indicate that InNbO is a new active material for phototransistors, but also suggest that InNbO‐based phototransistors have a great potential for the next‐generation interactive display technology. [ABSTRACT FROM AUTHOR]